In the electric knife sharpeners of the type that have been proposed so far, the slot or slots for the knife, and the grinding wheel are relatively arranged with the result that the quality of the sharpening very much depends on the skill of the user. In practice, this leads to uneven sharpening, faster grinding out of the knives to correct unevenly grounded spots or portions of the blade, and to a skill requirement that is beyond the possibilities of many people. More particularly, the electric knife sharpeners that have been proposed so far include at least one of the following disadvantages: their slots are arranged such that the knife is not positively guided all the way at the same angle relative to the grinding face; the pressure of the blade against the grinding wheel is not positively controlled and is entirely dependent on the skill of the user; the same slot is used for the left side and the right side of the blade and there is thus a problem to hold the blade at the same angle for both sides; the grinding wheel rotates in the front to rear direction against the blade and this produces a rough cutting edge with grainings on it.